1 /*
2 * linux/include/linux/cpufreq.h
3 *
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6 *
7 *
8 * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14 #ifndef _LINUX_CPUFREQ_H
15 #define _LINUX_CPUFREQ_H
16
17 #include <linux/mutex.h>
18 #include <linux/notifier.h>
19 #include <linux/threads.h>
20 #include <linux/device.h>
21 #include <linux/kobject.h>
22 #include <linux/sysfs.h>
23 #include <linux/completion.h>
24 #include <linux/workqueue.h>
25 #include <linux/cpumask.h>
26 #include <asm/div64.h>
27
28 #define CPUFREQ_NAME_LEN 16
29
30
31 /*********************************************************************
32 * CPUFREQ NOTIFIER INTERFACE *
33 *********************************************************************/
34
35 #define CPUFREQ_TRANSITION_NOTIFIER (0)
36 #define CPUFREQ_POLICY_NOTIFIER (1)
37
38 #ifdef CONFIG_CPU_FREQ
39 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
40 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
41 #else /* CONFIG_CPU_FREQ */
42 static inline int cpufreq_register_notifier(struct notifier_block *nb,
43 unsigned int list)
44 {
45 return 0;
46 }
47 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
48 unsigned int list)
49 {
50 return 0;
51 }
52 #endif /* CONFIG_CPU_FREQ */
53
54 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
55 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
56 * two generic policies are available:
57 */
58
59 #define CPUFREQ_POLICY_POWERSAVE (1)
60 #define CPUFREQ_POLICY_PERFORMANCE (2)
61
62 /* Frequency values here are CPU kHz so that hardware which doesn't run
63 * with some frequencies can complain without having to guess what per
64 * cent / per mille means.
65 * Maximum transition latency is in nanoseconds - if it's unknown,
66 * CPUFREQ_ETERNAL shall be used.
67 */
68
69 struct cpufreq_governor;
70
71 #define CPUFREQ_ETERNAL (-1)
72 struct cpufreq_cpuinfo {
73 unsigned int max_freq;
74 unsigned int min_freq;
75 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
76 };
77
78 struct cpufreq_real_policy {
79 unsigned int min; /* in kHz */
80 unsigned int max; /* in kHz */
81 unsigned int policy; /* see above */
82 struct cpufreq_governor *governor; /* see below */
83 };
84
85 struct cpufreq_policy {
86 cpumask_t cpus; /* affected CPUs */
87 unsigned int shared_type; /* ANY or ALL affected CPUs
88 should set cpufreq */
89 unsigned int cpu; /* cpu nr of registered CPU */
90 struct cpufreq_cpuinfo cpuinfo;/* see above */
91
92 unsigned int min; /* in kHz */
93 unsigned int max; /* in kHz */
94 unsigned int cur; /* in kHz, only needed if cpufreq
95 * governors are used */
96 unsigned int policy; /* see above */
97 struct cpufreq_governor *governor; /* see below */
98
99 struct work_struct update; /* if update_policy() needs to be
100 * called, but you're in IRQ context */
101
102 struct cpufreq_real_policy user_policy;
103
104 struct kobject kobj;
105 struct completion kobj_unregister;
106 };
107
108 #define CPUFREQ_ADJUST (0)
109 #define CPUFREQ_INCOMPATIBLE (1)
110 #define CPUFREQ_NOTIFY (2)
111
112 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
113 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
114 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
115 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
116
117 /******************** cpufreq transition notifiers *******************/
118
119 #define CPUFREQ_PRECHANGE (0)
120 #define CPUFREQ_POSTCHANGE (1)
121 #define CPUFREQ_RESUMECHANGE (8)
122 #define CPUFREQ_SUSPENDCHANGE (9)
123
124 struct cpufreq_freqs {
125 unsigned int cpu; /* cpu nr */
126 unsigned int old;
127 unsigned int new;
128 u8 flags; /* flags of cpufreq_driver, see below. */
129 };
130
131
132 /**
133 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
134 * @old: old value
135 * @div: divisor
136 * @mult: multiplier
137 *
138 *
139 * new = old * mult / div
140 */
141 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
142 {
143 #if BITS_PER_LONG == 32
144
145 u64 result = ((u64) old) * ((u64) mult);
146 do_div(result, div);
147 return (unsigned long) result;
148
149 #elif BITS_PER_LONG == 64
150
151 unsigned long result = old * ((u64) mult);
152 result /= div;
153 return result;
154
155 #endif
156 };
157
158 /*********************************************************************
159 * CPUFREQ GOVERNORS *
160 *********************************************************************/
161
162 #define CPUFREQ_GOV_START 1
163 #define CPUFREQ_GOV_STOP 2
164 #define CPUFREQ_GOV_LIMITS 3
165
166 struct cpufreq_governor {
167 char name[CPUFREQ_NAME_LEN];
168 int (*governor) (struct cpufreq_policy *policy,
169 unsigned int event);
170 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
171 char *buf);
172 int (*store_setspeed) (struct cpufreq_policy *policy,
173 unsigned int freq);
174 unsigned int max_transition_latency; /* HW must be able to switch to
175 next freq faster than this value in nano secs or we
176 will fallback to performance governor */
177 struct list_head governor_list;
178 struct module *owner;
179 };
180
181 /* pass a target to the cpufreq driver
182 */
183 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
184 unsigned int target_freq,
185 unsigned int relation);
186 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
187 unsigned int target_freq,
188 unsigned int relation);
189
190
191 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy);
192
193 int cpufreq_register_governor(struct cpufreq_governor *governor);
194 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
195
196 int lock_policy_rwsem_read(int cpu);
197 int lock_policy_rwsem_write(int cpu);
198 void unlock_policy_rwsem_read(int cpu);
199 void unlock_policy_rwsem_write(int cpu);
200
201
202 /*********************************************************************
203 * CPUFREQ DRIVER INTERFACE *
204 *********************************************************************/
205
206 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
207 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
208
209 struct freq_attr;
210
211 struct cpufreq_driver {
212 struct module *owner;
213 char name[CPUFREQ_NAME_LEN];
214 u8 flags;
215
216 /* needed by all drivers */
217 int (*init) (struct cpufreq_policy *policy);
218 int (*verify) (struct cpufreq_policy *policy);
219
220 /* define one out of two */
221 int (*setpolicy) (struct cpufreq_policy *policy);
222 int (*target) (struct cpufreq_policy *policy,
223 unsigned int target_freq,
224 unsigned int relation);
225
226 /* should be defined, if possible */
227 unsigned int (*get) (unsigned int cpu);
228
229 /* optional */
230 unsigned int (*getavg) (unsigned int cpu);
231 int (*exit) (struct cpufreq_policy *policy);
232 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
233 int (*resume) (struct cpufreq_policy *policy);
234 struct freq_attr **attr;
235 };
236
237 /* flags */
238
239 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
240 * all ->init() calls failed */
241 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
242 * "constants" aren't affected by
243 * frequency transitions */
244 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
245 * mismatches */
246
247 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
248 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
249
250
251 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
252
253
254 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
255 {
256 if (policy->min < min)
257 policy->min = min;
258 if (policy->max < min)
259 policy->max = min;
260 if (policy->min > max)
261 policy->min = max;
262 if (policy->max > max)
263 policy->max = max;
264 if (policy->min > policy->max)
265 policy->min = policy->max;
266 return;
267 }
268
269 struct freq_attr {
270 struct attribute attr;
271 ssize_t (*show)(struct cpufreq_policy *, char *);
272 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
273 };
274
275
276 /*********************************************************************
277 * CPUFREQ 2.6. INTERFACE *
278 *********************************************************************/
279 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
280 int cpufreq_update_policy(unsigned int cpu);
281
282 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
283 unsigned int cpufreq_get(unsigned int cpu);
284
285 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
286 #ifdef CONFIG_CPU_FREQ
287 unsigned int cpufreq_quick_get(unsigned int cpu);
288 #else
289 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
290 {
291 return 0;
292 }
293 #endif
294
295
296 /*********************************************************************
297 * CPUFREQ DEFAULT GOVERNOR *
298 *********************************************************************/
299
300
301 /*
302 Performance governor is fallback governor if any other gov failed to
303 auto load due latency restrictions
304 */
305 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
306 extern struct cpufreq_governor cpufreq_gov_performance;
307 #endif
308 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
309 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
310 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
311 extern struct cpufreq_governor cpufreq_gov_userspace;
312 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
313 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
314 extern struct cpufreq_governor cpufreq_gov_ondemand;
315 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
316 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
317 extern struct cpufreq_governor cpufreq_gov_conservative;
318 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
319 #endif
320
321
322 /*********************************************************************
323 * FREQUENCY TABLE HELPERS *
324 *********************************************************************/
325
326 #define CPUFREQ_ENTRY_INVALID ~0
327 #define CPUFREQ_TABLE_END ~1
328
329 struct cpufreq_frequency_table {
330 unsigned int index; /* any */
331 unsigned int frequency; /* kHz - doesn't need to be in ascending
332 * order */
333 };
334
335 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
336 struct cpufreq_frequency_table *table);
337
338 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
339 struct cpufreq_frequency_table *table);
340
341 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
342 struct cpufreq_frequency_table *table,
343 unsigned int target_freq,
344 unsigned int relation,
345 unsigned int *index);
346
347 /* the following 3 funtions are for cpufreq core use only */
348 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
349 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
350 void cpufreq_cpu_put (struct cpufreq_policy *data);
351
352 /* the following are really really optional */
353 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
354
355 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
356 unsigned int cpu);
357
358 void cpufreq_frequency_table_put_attr(unsigned int cpu);
359
360
361 /*********************************************************************
362 * UNIFIED DEBUG HELPERS *
363 *********************************************************************/
364
365 #define CPUFREQ_DEBUG_CORE 1
366 #define CPUFREQ_DEBUG_DRIVER 2
367 #define CPUFREQ_DEBUG_GOVERNOR 4
368
369 #ifdef CONFIG_CPU_FREQ_DEBUG
370
371 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
372 const char *fmt, ...);
373
374 #else
375
376 #define cpufreq_debug_printk(msg...) do { } while(0)
377
378 #endif /* CONFIG_CPU_FREQ_DEBUG */
379
380 #endif /* _LINUX_CPUFREQ_H */
381
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